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Ars System Guide: HTPC edition

The Ars System Guide returns with a twist: this month we spec out an HTPC box …

Introduction

A mainstream operating system finally makes the home theater PC (HTPC) for the masses a reality. In the past, there have been attempts at hacking together an HTPC-type device, with smaller companies offering solutions, but without widespread support and marketing, these efforts never successfully penetrated the mainstream. The first version of Windows Media Center Edition was available only with the purchase of a prebuilt HTPC system from an OEM. With the release of Windows Media Center Edition (MCE) 2005 enthusiasts can now put together their own dream HTPC.

Windows (MCE) 2005 offers an attractive, easy-to-use interface combined with hardware support that makes it easier to build an HTPC that is a true media box: TV recording with time shifting and channel guide, streaming audio, DVD-recording and DVD-playback, radio, web browsing, along with all the functions of a standard PC. Truly functional channel guides and intelligent recording are things that TiVo and ReplayTV users are long familiar with. Today's cheap hard drive space mean many hours of video can be recorded, which makes the replacement of the VCR both practical and extremely attractive.

Time-shifting is one of the functions that requires a fair amount of CPU time. In order to build a fully functional HTPC, that requires reasonably up-to-date system to handle time shifting and encoding. Lots of hard disk space for recording is a major benefit that should not be overlooked, particularly with the presence of affordable, gigantic hard drives. A second TV tuner adds tremendous flexibility for simultaneous viewing and recording to any HTPC, which makes for additional capability at some additional cost. Using a case that blends in with your home theater is another nice touch that many appreciate. To take advantage of the capabilities of MCE 2005, a fairly modest system with a lot of drive space is an excellent way to start.

Stacking on high-defintion TV (HD) as a requirement further ups the hardware requirements, requiring increases in CPU power, drive space, and video card capabilities. Naturally, quite a bit more capable hardware than a simple modest system is going to be necessary, particular when attempting timeshifting simultaneously with other functions in HD.

An extremely low-cost HTPC is achieved most easily by eliminating fancy requirements such as time-shifting and dual tuners. A large hard drive is a requirement for optimal flexibility, but those who demand less from their HTPC setup can let their recording requirements dictate how much smaller their drives can be.

What makes an HTPC special

Everything we've listed above can be done by an ordinary PC with the right software and TV tuner or two. The differneces with a HTPC are primarily in software, form factor, and noise requirements.

With a television, you typically deal with a lower resolution and a much longer viewing distance compared to a computer monitor, so a simplified user interface with larger icons and text is necessary to comfortably use an HTPC from your couch, ten feet from your TV. The functions typically accessed by a HTPC are more limited than a standard PC, so the low resolution interface with large icons must be properly done.

Boring beige boxes that house the stereotypical PC are not usually welcome in most people's living rooms. They want PC functionality without advertising, or at least without the disruption of their decor. Hiding a typical ATX chassis like the In-Win S508 or even the dark grey Antec SLK3700AMB is not the easiest thing to do. Some may find small form factor (SFF) boxes as a solution, but the typical cube shape is difficult to integrate into most home theater setups. Chassis aimed at the HTPC market tend to make efforts to blend in with audio/video gear, particularly the smaller microATX chasses done in black finishes with hidden drive bay doors. Larger ATX chasses done in black or brushed aluminum do not blend in quite so easily, but with considerable effort from Silverstone, Ahanix, Soldam, Coolermaster, and others, the specialized HTPC chassis market is alive and well.

Keeping a HTPC unobtrusive involves paying attention not only to looks, but noise. The whirr of cooling fans and whine of drive seeks are unacceptable intrusions when trying to enjoy a movie or listen to music. A basic HTPC may not need extensive work to keep noise levels low compared to their high-powered counterparts, but addressing the details is still important in making the HTPC experience a quiet one. Thicker sheet metal, acoustic damping foam, side-intakes to reduce internal noise leakage, and acoustically isolated had drive mounts are all possibilities. Careful selection of quiet CPU coolers, less-intrusive drives, and low-noise power supplies are also recommended.

In short, why?

Those prone to fits of random computer upgrades brought on by geek lust need few additional reasons to build an HTPC. It is just fun to do, almost as much fun to play with once it is built.

As a practical measure, an HTPC can handle many functions in one box, replacing a host of individual devices. All of the components in your home entertainment system ? VCR, digital video recorder (TiVo or ReplayTV), stereo tuner, DVD-recorder, DVD-player, media server ? can be supplanted by an HTPC. The simple attraction of one device equalling fewer wires and power cords is an important detail to many.

We introduce two flavors of HTPCs in this guide: the Hot Rod HTPC and the Budget HTPC. The Hot Rod does dual tuners and has enough hardware to handle simultaneous time-shifting, streaming, HD, and all the goodies. The basic system loses quite a bit of muscle, but is an excellent platform that still handles regular time-shifting and other duties nicely.

A note on terminology: we refer to the "high-end" setup as the Hot Rod and the "low-end" setup as the Budget Box, just as we do in the normal Ars System Guide. The Hot Rod HTPC and Budget HTPC are not to be confused with their conventional counterparts, even if the naming intention and naming conventions are similar.